Float for aeroplanes.



M. L. BRISTOL 6: H. C. RICHARDSON.

. FLOAT FOR AEROPLANES. v

APPLlCATiON FILED FEB. 2|. I916. L213,%& .mented Jan. 23,1917.

I a SHEETS-SHEET 1.

M. L. BRISTOL H. C. RICHARDSON.

FLOAT FOR 'AEROPLANES.

APPLICATION. mm) FEB. 2|, 19m.

Patented Jan.23,19.17.

3 SHEETSSHEET 2.

M. BRISTOL & H. c. RICHARDSON.

FLOAT FOR AEROPLANES.

ARRLLCATION ElLED FEB. 2|, Hilfi- 1917. 3SHEETS-SHEET 3.

Patented Jan. 23,

ferns r ween mom sors 'ror. sw m Hermon cnns'ren mcnonoson', or one more STATES NAVY.

ricer ron sworn ewes.

To all 'wl'wm it may concern Be it known that we, MARK LAMBERT Bms'ron and Hermon CHESTER RICHARDSON, both of the United States Navy, and citizens of the United States, stationed at Washington, in the District of Columbim have invented certain new and useful Improvements in Floats for Aeroplenes; and we do hereby declare the following to be olull, clear, and exact description of the invention, such as will enable others skilled in the art to which it oppertains to make and use the some. I

(Bur invention relates to improvements in aeroplanes, and itis intended to provide an aeroplane that will have the following qualities: stability at rest in smooth or rough water; ready steering on the surface in smooth or rough water; absence of danger when skidding in smooth or rough water; diminution of squatting; reduction of shocks on lending, or when running on roughweter at sneeds; early planing; practical elosence o porpoising; practical absence of dis tllrbijlg forces when melting or breaking contest with the surface; easy penetration wove crests; protection of the prooeller end of the win tips in rough yvoterg lloeqoate stability when even solid *weter posses over the floats; and minimum resistonce of the il-oats in flight through the air. M l se advantages are in a. large osnre obtained by use of the apparatus r described. sense is lied to the accompanying drawings, in which similar parts ore indihy similar reference symbols throughoottlie se /oral views.

Figure 1 a perspective view showins the central portion of e hydroeeroplene with the improved floats ,ottsched; Fig. 2 is e plan view of the i'ioets shown Fig. 1, parts hein broken away, and most of the bracing being omitted iorthe sake of cleerness in the drawings; Fig. 3 is a side elevation showthe central float, end one of the side floats, on e larger scale than in Fig. l; Fig. .i: shows e central longitudinal vertical section, or inhoerd profile, through the central or main float, the keel being shown in elevation; Fig. 5 shows a. central longitudinel vertical section, or inboard profile,

through one of the smaller floats Fig. 6

shows e'section along the line 66 of Fig.

2, and looking in the direction of the orrows; '3 shows o section along the'line t -Tl specification of Letters Patent.

of Fig; 2, and looking in the direction of the 'errows; Figs. 8, 9, 1G and 11 show sections corresponding to the lines 8 l8 9-- '10*---1() and 1l'1l of Fig. l, and looking in the direction of the errows; Figs. 12 and 13 show sections along the lines 12 -12 and 199-13 of Fig.- 5, and looking in the direction of the arrows; Fig. 14 shows what is lmown in shipbuilding as a. body plan of the main float, the lines on the right-hand side of the figure indicating the sections as seen from the bow of the float, and the lines on the left-hand side of the figure indicating the sections as seen from. the stern of the the construction and arrangement oi? the group of floats which are I carried by the aeroplane and support the some'when in the water, and which are constructed of streorm line form to minimize the resistance of he sir, and also to penetrate the crest of woves There are three of these floats connected together in e group, es shown in 1 to end comprisin a, control or rosin fleet end side lloets l) and D connect d the main idoot, and to eech other, by sui trusses G, U, C end (P, shown roost else ly in Fig l, The two smaller fleets preferably located nearer the lonoitudinel axis of the resin fleet, which corresponds to the central longitudinal sxis oi-the complete machine, then are tips of the wings, so test when the machine is lighting, the smaller side iloots "will engage the wetor heiore the tips or the wines can do so, and thus there will he no excessive strain brought on the tips of the wings, in practice, we looete these side floats at about one-third or two fifths the distance from the center of the machine to the tip oi the wing, The errangement of these trusses would very with the construction oi the sore lone, end may be varied at will. Any suitable construe *tion of suficie'ntstrength end elssticity to Patented 91 en, 23, will,

Application filed February 21, 1916. Serial lto. 79,695.

' attach the floats to the aeroplane may be bracing the float s, or connecting the same to the aeroplane.

The main float B should be of suflicient buoyancy to support the weight of the aeroplane and its load, and the smaller floats with the'main float should have sufficient reserve buoyancy for the "successful operation of the aeroplane. The smaller side floats are arranged at. each side of and abreast the. rear portion of the main float, as shown in Fig. 2, and these floats are so arranged that the center of gravity of the aeroplane will practically coincide with the center of flotation of the group of floats indicated by X. in Figs. 2 and 3. The advantage of this arrangement will be hereinafter more fully described. .The main float Bis made of strea rn line'form, asshown, and is provided with a curved upper portion 1), as shown in Figs. 6 to 11 and 14, and has its bottom slightlywarped fore and aft, but rectilinear in cross section, as shown in Figs." 6 to 11 and 14, the two'sides of the bottom converging toward the central keel. The

two flaring sides of the bottom are slightly warped in reverse directions fore and aft,

as shown in Fig. 14;, for reasons that will hereinafter ber described. The main float B also provided'with a suitable keel B mainly for landing purposes. The shell of the float, ifpf-wood, is preferably made of multiple thicknesses of planking, such as; two-ply spruce planking with cloth and water-proofglue between the layers, so as to make the same water-tight. 0n the interior we provide av center keelson 13 running vthe full length of the float, and we also provide suitable transverse ribs b transverse watertight bulk heads 6?, stanchions' b and fore and aft bracing b. The central portion of the float on which the main shock is felt in lending, org-in; striking the water with great force, is provided with a vertical longitudinal bulk head 6, and intermediate keelsons b, or longitudinal frames, are also provided. Thetransverse bulk heads bflif of.

wood, are preferably made of multiple thicknesses-of planking, one placed horizontally and others placed diagonally, as shown in Figs. 9 and 10, so that greatstrength is secured against blows on the-bottom of the float as when striking the water at high speed. The boards of the longitudinal bulk head b and the braces b arefor similar reasons made inclined, as shown, so as to stiffen relates the hull of the float when striking the water.

Other suitable stiffening means maybe pro- ,vided on the interior of the floats, such as the frames 6 shown in Figs. 9, 10 and 11, and the struts I), shown in Figs. 6 and 7.

By the construction shown the main float is divided into a series of water-tight compartments, two. being shown in the forward portion of the float, one in the stern portion,

and. two in the central portion, separated by. the central fore and aft bulk head I).

The construction of the smaller'fioats D 'and D is generally similar to that of the in Figs. 12 and 13, and warped bottoms d which are rectilinear in cross section. On

keelsons d and (1 running fore and aft, and with transverse bulk heads (1 and with suitable braces clflpreferably diagonally disposed to give longitudinal stiffness to the The transverse v float, and-with struts d bulk heads i if of wood, are preferably made of multiple layers, as shown in Fig. 13,

' stream-line form, as shown in the drawings,

more especially in Figs. 14 and 15', in which the nature of the warped'bottom of the main and-smaller floats is indicated by the inclined straight lines, and the curved top portion of said floats indicated by the curved lines. The curveddotted lines indicate the position of the side keelsons. The line LW-L indicates the load water line. The. several sections shown in Fig. 14 indicated by the lines 2, 4, 6, 8, 10, 12, 1e and 16 correspond with the sections along the line 2'2, H, etc., and 18-18 of Fig. 2; and the. lines 2", 4r, 6, 8' of Fig. 15 corresponding to sections along the line 22', 44-1, 6'6 and 8' 8' of Fig. 2, respectively. It will be noted that these bottom section lines 2 to 18 and 2'" to 8' are not parallel, but in the'larger float the bottom surfaceis warped" to form a warped surface of double curvature; while in the smaller floats the bottom surface is warped to form a warped surface of single curvature.

The advantage of the warping of the main float is to provide the necessary cushioning near the step, and at the same time to pro-- vide {ample bearing power at the bow, to'

prevent the nose from being buried on a landing. .The change in flare of: the side floats is to provide a similar cushioning ef- .the interior these floats are provided with I feet, and also the increased angle of flare '125 at the bow is to prevent the side floats from burying-the nose on a skidding landing.

The floats are preferably so adgusted relative to the aeroplane that when at rest on smooth water the floatsare down by the gives a very advantageous angle for the planing efi'ect in starting, and also gives the wings a greaterlifting' angle, both tending to cause "planing more readily.

It will be seen that we provide a central float of suitable stream-line form and construction of the hydroplane type,ot such proportions as to support the major portion of the displacement at rest, together with suitable reserve buoyancy, and so formed as to resist and reduce shocks on landings, or when planing at high speed in rough water; also so shaped as to avoid danger due to skidding on the surface. addition to this central float we provide symmetrically rearwardly, laterally and relatively upwardlydisposed floats of suitable stream-line form and hydroplane type, and of such proportion as to provide a minor portion of the displacement at rest, together with suitable reserve buoyancy; and so formed as to resist and reduce shocks on landing orwhen planing at high speed in rough water; and also so formed as to avoid danger due to skidding on the surface and, at the same time, of such form asto assist in steering; the whole being designed so that at rest the floats are trimmed by the stern about 3, the center of buoyancy then being im ni'ediately under. the center of gravity.

The operation of the apparatus is as follows :-Suppose the aeroplane to be at rest on the water, and it be desired to getaway, as the boat skims along the Water the Wings and the bottoms of the floats cause it to lift on an even heel, and the side floats will be the first to be lifted out of the water, leaving the lower portion or the main float submerged, and as the speed increases above a certain point the how from the step of the main float clears the after portion the main float, the remaining load now being carried at the step, and the main heat will shortly thereafter be lifted clear of the water, and the aeroplane will continue its flight through the air. New in the process of rising from the water, the planof the two side floats, before the speed gets very high, will prevent any material squatting, and they assist in breaking the suction to the rear of the step of the main float, and thus the equivalent of the well known stepped type is secured, without the defects inherent in that type where the steps work in the wake of the forward portion.

Should the sea be choppy, or rough, theshape of the floats will permit them to readily penetrate the crests of the waves. Among other features and advantages of the hereinbefore described construction and operation we may include the following quired stability on the surface with reserve buoyancy and range of stability to the required degree.

The centralized group avoids undue stress on the wing structure and provides initial stability in c'ontradistinction of the instability of the usual three-float arrangement with the planing floats on the wing tips. No tail floats arerequired to prevent tipping over backward. This arrangement of floats has structural advantages, concentrating the principal Weight and strength members so that the principal members contribute strength where required, and thus avoiding undue stresses on the wing structure when getting away, flying, or landing, such as are involved when Wing tip floats, or twin iioats, are used. The reserve buoyancy is preferably such that the central float has a total displacement at least equal to the full loadot the aeroplane, so that when riding the crest of a Wave the propeller and wing clearances are still the same as the clearance from the deck of the main float, and in a trough, unless it is a sharp one, the side floats are satisfactorily elevated relative to the central float, so that the principal load is still carried on the central float. To appreciate the advantage this afiords, it should be noted that twin floats straddle crests and thus in choppy water endanger a central propeller, which would be protected in a triple float type. Also, in a triple float the stability is due more to separation of floats than to the displacement of the lateral lidats; and though equal stability is provided the rolling couples, on account of the elevation of the side floats, provide more flexibility, and the action is less harsh than with a twin float disposition in which hall the load is carried necessarily on each float. I

Under wa. .As the side floats carry load up to a certain speed their planing bottoms provide the additional surface required for planing-up to the time that the main float has sm'iicicnt planing power to handle the remaining load. The transition is progressive, and the planing bottoms of the side iioats are in effect a variable step which is designed to work clear of the wake of the forward bottom (oi the main float) lfhis type is more efficient, planes quicker, and reduces the porpoising tendency present in the usual step type; in fact, the side floats act under ,.way as dynamic stabilizers, later ally and longitudinally, acting in conjunction with the air controls up to the time the latter are sufficient for the purpose.

to the daring form of the bottoms ot the side floats, they also ofler strongdynamic forces resisting overturning sidewise when skidding on the surface, and this same form of bottom materially assists in steering on the surface because the higher speed of the outer float on a turn causes it to plane better than its partner, which action com bined with the skidding action. above referred to causes the inboard float to drag harder, and thus provides a strong turning moment in addition to that provided by the air rudder.

At a moderate speed, due to the assist- I ance of the planing powers of the bottoms of the side floats, the planing power of the.

main float is improved, as it cannot squat; and the planing of the systemis inaugurated at an early stage, and the transition from planing on all three floats to planing on the central float is smooth'and rapid.

The bottom of the main float hasa V form for the purpose ofbreaking the shock porting members.

on landing, or when running over the surface of rough water at high speed. This natural shock absorber avoids the necessity of mechanical shock absorbers in the supdanger when skidding on the surface. The central system is so arranged that the first point of contact onlanding is on the bottom of the main float nearly under the center of gravity. This affords structural advantages due to the centralization of the disturbing forces involved when contact with the surface is made, or broken, and the \l-bottom also contributes to reduce the sharpness with which these forces come into play.

It will be obvious that'various modifications might be made in the herein described apparatus, andin the construction, combination and arrangement of parts which could be used without departing from the spirit of our invention. Having thus described our invention what we claim and desire to secure by Letters Patent of the United States is 1. A float attachment for aeroplanes, comprising a main-central float mounted below the center of gravity of the aeroplane and provided with a substantially V-shaped bottom, and two smaller. side floats secured abreast the rear portion of the main float, the three floats being mounted below and connected to the body of the aeroplane and This form also avoids portion of the main float, the two side floats. having their upper surface curved and tapering fore and aft and their bottoms flaring. r

upward and outward in reverse directions, the three floats being also connected to the body of the aeroplane, substantially as described.

3. A float attachment for aeroplanes, com prising a main central float mounted below the center of gravity of the aeroplane, said float being of stream-line construction having its'upper surface curved and tapering forward and aft, and its bottom substantially ll-shaped in cross section, and provided with a step, and two smaller side floats secured abreast the rear portion of the main float, the two side'floats having their upper surface curved and tapering fore and aft and their bottoms flaring upward and outward in reverse directions, the three floats being also connected to the body of the aeroplane, substantially as described.

4. A float attachment for aeroplanes, comprising a main central float mounted below the center of. gravity of the aeroplane, said float being of stream-line construction having its upper surface curved and tapering forward and aft, and its bottom substantially V-shaped in cross section, and pro- .vided with a step, with means for ventilating said step, and two smaller side floats secured abreast the rear portion of the main float, the two side floats having their upper surface curved and tapering fore and aft and their bottoms flaring upward and outward in reverse directions the three floats being also connected to thebody of the aeroplane, substantially as described.

'5. A float attachment for aeroplanes, comprising 'a main central float mounted below the center of gravity of the aeroplane, said float bemg of stream-line construction having its upper surface curved and tapering forward and aft, and its bottom substan-' tially \I-shaped in cross section, and two smaller side floats secured abreast the rear portion of the main float, the two side floats having their upper surface curved and tapering fore and aft and. their bottoms of warped construction and flaring upward and outwardm reverse directions,the three floats being also connected to the body of the aeroplane, substantially as described.

6. A float attachmentfor aeroplanes, comprising a main central float mounted below the center of gravity of the aeroplane, said float being of stream-line construction having its upper surfaces curved and tapering forward and aft, and its bottom substantially V-shaped in cross section, and provided with a step, and two smaller side floats secured abreast the rear portion of the main float, the two side floats having their upper surface curved and tapering fore and aft and their bottoms of warped construcrelease tion and flaring upward and outward in reverse directions, the three floats being also connected to the body of the aeroplane, substantially as described.

7. A float attachment for aeroplanes, comprising a main central float mounted below the center of gravity of the aeroplane, said float being of stream-line construction having its upper surface curved and tapering forward and aft, and its bottom substantially V-shaped in cross section, and provided with a step, with means for ventilat ing said step, and two smaller side floats secured abreast the rear portion of the main float, the two side floats having their upper surface curved and tapering fore and aft and their bottoms of warped construction and flaring upward and outward in reverse directions, the three floats being also connected to the body of the aeroplane, substantially as described.

8. A float attachment for aeroplanes, comprising a main central float mounted below the center of gravity of the aeroplane, two smaller side floats secured abreast the rear portion of the main float, the two side floats having their upper surface curved and tapering fore and aft and their bottoms of warped construction and flaring upward and outward in reverse directions, thethree floats being also connected to the body of the aeroplane, substantially as described.

9. A float attachment for aeroplanes, comprising a main central float mounted below the center of gravity of the aeroplane, said float being of stream-line construction having its bottom substantially V-shaped in cross section, and. provided with a step, and two smaller side floats secured abreast the rear portion of the main float, the two side floats having their upper surface curved and tapering fore and aft and warped construction. and flaring upward and outward in reverse directions, the three floats beingalso connected to the body of the aeroplane, substantially as described.

10. A float attachment for aeroplanes, comprising a main central float mounted below the center of gravity of the aeroplane,

said float being of stream-line construction,

its bottom substantially ll-shaped in cross section, and provided with. a step, with means for ventilating said step, and two smaller side floats secured abreast the rear portion of the main float, the two side floats having their upper surface curved and tapering fore and aft and their bottoms of warped construction and flaring upward and outward in reverse directions, the three floats being also connected to the body of the aeroplane, substantially as described.

11. A float attacent for aeroplanes, comprising a main central float mounted below the center of gravity of the aeroplane,-

said float being of stream-line construction,

and

their bottoms of and its bottom substantially V-shaped in cross section, and two smaller side floats secured substantially abreast the rear portion of the main float, the two side floats having their upper surface curved and tapering fore and aft and their bottoms flaring upward and outward in reverse directions, the three floats being also connected to the body of the aeroplane, and forming a central triangular support therefor when. engaging the water, substantially as described.

12. A float attachment for aeroplanes, comprising a main central float mounted below the center of gravity of the aeroplane, said float being of stream-line construction having its upper surface curved and tapering forward and aft, and its bottom substantially ll-shaped in cross section, and provided with a step, and a keel, and two smaller side floatssecured substantially abreast the rear portion of the main float,

the two side floats having their upper sur- 7 face curved and'tapering fore and aft and their bottoms flaring upward and outward in reverse directions, the three floats being also connected to the body of the aeroplane, and forming a central triangular support therefor when engaging the water, substantially as described,- 1

13. A float attachment for aeroplanes, comprising a main central float mounted below the center of gravity of the aeroplane, said float being of stream-line construction having ing forward and aft, and its bottom substantially V-shaped in cross section, and pro vided with a heel and a step, with means for ventilating said step, and two smaller side floats secured substantially abreast the rear having their upper surface curved and tapering for and aft and their bottoms flaring upward and outward in reverse directions, the three floats being triangular support therefor when engaging the water, substantially as described.

14. A float attachment for hydroaeroplanes, comprising a main central float mounted below the center of gravity of the aeroplane, and two smaller side floats seits upper surface curved and taper- -portion or" the main float, the two side floats s also connected to the body of the aeroplane, and forming a central i cured abreast the rear portion of the main mounted below and connected to the body of the aeroplane,

15. A float attachment for hydroaeroplanes, comprising a main central float mounted below the center of gravity of the aeroplane, and provided with a substantially substantially as described.

V-shaped bottom, and two smaller side floats 13a secured. abreast the rear portion of the main float, and having their rear ends terminating at points substantially in line with the rear end of the main float, said smaller floats being located nearer the center of the wings than the tips thereof, the three floats being mounted below and connected to the body of the aeroplane, substantially as described.

16. A float attachment for aeroplanes, comprising a main central float mounted below the center of gravity of the aeroplane, said float being of stream-line construction having its upper surface curved and tapering forward and aft, and its bottom substantially V-shaped in cross-section, and two smaller side floats spaced away from and secured abreast the rear portion of the main float, and having their rear ends terminating at points substantially in line with the rear end of the main float, said smaller floats be ing located nearer the center of the wings than the tips thereof, the three floats being also connected to the body of the aeroplane, substantially as described.

In testimony whereof, we aflix' our signatures.

MARK LAMBERT BRISTOL.

HOLDEN CHESTER RICHARDSON. 

